For Conrail engineer Ricky L. Gates, the Sunday trip from Baltimore to Harrisburg was a four- or five-hour job that would net him two days' pay under union rules.

"The main thing going through my mind was, 'This is great, and I'll still be in the bars with my friends this evening,' " Mr. Gates said.

The milk run became a party on that January day in 1987, when brakeman Edward Cromwell lighted up a marijuana joint and passed it to his engineer.

But less than 18 minutes later, their blunders had carried the locomotives into the path of a speeding Amtrak passenger train, spiraling the "party" into a twisted, flaming train wreck that killed 16 people, injured 170 and changed Mr. Gates' life forever.

Over cigarettes and coffee last week, in a diner near the Oakview Treatment Center in Ellicott City where he works as a counselor after serving four years in prison, Mr. Gates talked candidly about what he calls "my accident."

He spoke of the twin addictions -- alcohol and marijuana -- that by 1987 had already wrecked his family and cost him many friends. He also talked about his continuing struggle with guilt and shame, a sobriety now more than 6 years old, and a sense of self-worth found in helping others.

"I wouldn't trade a day of what I'm going through now for any of those so-called 'good times' I had in the past," he said.

Mr. Gates, 38, has tried to avoid publicity since the accident. He offered to be interviewed only to defend Michael S. Gimbel, Baltimore County's substance-abuse director.

Mr. Gimbel came under fire in The Sun's letters-to-the-editor columns after he cited the Chase train wreck as an example of the dangers of marijuana use.

The letter-writers -- at least one of them an advocate of marijuana legalization -- sought to downplay the role of marijuana in the crash. But Mr. Gates says they're wrong.

"If the joint hadn't been there, I wouldn't have been so inattentive," he said. "I feel it was pretty much exclusively the marijuana -- the marijuana and the disease of addiction."

Ricky Gates today is a slim, polite, soft-spoken man with gray-blue eyes. His hair and neatly trimmed mustache are graying. The beard in those 1987 news photos is gone.

Brakeman got immunity

He served almost two years of a five-year state sentence for manslaughter by locomotive, then two more years of a three-year federal sentence for lying to investigators.

Mr. Cromwell, his brakeman, received immunity in exchange for his testimony.

At the request of crash victims and their families, Mr. Gates testified in favor of federal legislation that now requires random drug testing for transportation. He also provided depositions in civil suits that arose from the accident.

It was difficult for him, he said, but "it was a matter of making amends."

He was released in April 1992 and completed his supervised probation in September.

In prison, Mr. Gates entered a drug treatment program, and he says he has been sober for more than six years. He also took addiction-counseling courses offered in prison by Essex Community College.

Now a counselor

After a series of jobs painting houses and waxing cars, he began work in November as a midnight shift counselor at Oakview, helping patients through late-night crises.

"I felt so shameful for a whole lot of reasons, but I found that by trying to help others, I could help myself, too," he said.

Thomas G. Taylor, director of treatment at Oakview, said Mr. Gates has been "a real positive addition" to the staff. "He has his own program of recovery that he's real active in, and he's fairly open with the patients about his own life, where drug abuse took him and the shame and guilt he's had to live with."

He is also rebuilding his family.

"My daughters [now 14 and 15], were quite bitter at me for a while, for the shame I brought to the family," he said. "But we're resolving that. I think we get along pretty well now."

In 1987, Mr. Gates' life centered on getting high. "I had already lost my family and all the friends associated with my marriage. I had isolated myself to protect my right to do drugs and drink," he said.

He was a beer drinker, but the bars and their parking lots, he said, were also where he bought his marijuana, "the kind of high I liked best."

Although he said he had six to eight beers in a bar the night before the accident, he went home and slept well until 10:15 a.m., when Conrail called him to work.

'Disease of addiction'

"I felt good when I woke up," he said, and, contrary to suggestions by investigators, was "as sober as can be." But "the disease of addiction was still talking."

In his eagerness to get going so he could return to the bars and get high, he said, he skipped critical safety checks that would have shown that the alerter -- a whistle that warns the crew of signal changes -- had been silenced with duct tape.